In recent years, the use of flat panel displays that are thin and can display in a small display area has been spreading. In liquid crystal display panels, which are one type of panel for such flat panel displays (FPD), two glass substrates are bonded together and liquid crystal is injected into the gap between these, and thus, a display panel is formed. Bonded mother substrates where glass substrates are bonded together are usually divided into a predetermined size by means of an apparatus for processing substrates.
“Divide” means to draw a scribe line (cutting line) on a substrate, and then apply force to the substrate where the scribe line has been drawn, so that the substrate is broken along the scribe line.
In addition, the term “divide” includes cases where a substrate is separated along a scribe line or becomes of a state immediately before separation as a result of the scribe line being drawn using a blade that can cause deep vertical cracking.
Patent Document 1 (Japanese Unexamined Patent Publication H11 (1999)-116260) discloses an apparatus for processing glass using which a bonded mother substrate can be scribed and divided into a desired size.
Patent Document 1: Japanese Unexamined Patent Publication H11 (1999)-116260
Meanwhile, liquid crystal display panels for television receivers and monitors of personal computers have been increasing in size year by year, and mother substrates which are used for the production of liquid crystal display panels have also been increasing in size year by year. Such large scale mother substrates are divided, and thereby, a large number of unit substrates are manufactured. In the process for manufacturing a large number of unit substrates from a large scale mother substrate, an apparatus for conveying a substrate is used in order to convey mother substrates and unit substrates between respective stages.
Apparatuses for conveying a substrate are usually provided with a vacuum suction mechanism which can suck a substrate as those described above through vacuum, a mechanism for turning a substrate over, in which a substrate that has been sucked by the vacuum suction mechanism through vacuum is turned over, and at least one conveying robot which has a moving mechanism for supporting and moving these mechanisms in the direction of the X axis and the Y axis.
When a mother substrate is divided, first a cutter wheel chip is rolled over a mother substrate on top of a table in a state where a predetermined scribing pressure is applied, and thereby, a scribe line is drawn on side A, which is one side of the substrate. Next, the substrate is sucked and turned over, and after that, pressure is applied with a breaking bar or the like to side B of the substrate, which is the rear side of side A of the substrate, so that side A of the substrate is broken. Next, in the same manner as in the above, a scribe line is drawn on side B of the substrate, and the substrate is sucked and turned over, and after that, pressure is applied with a breaking bar or the like to side A of the substrate, so that side B of the substrate is broken. Alternatively, a scribe may be drawn on side A of a substrate, and then, the substrate may be sucked and turned over, and after that, a scribe line may be drawn on side B of the substrate, and subsequently, pressure may be applied with a breaking bar or the like to side B of the substrate, so that side A of the substrate is broken, and the substrate may be sucked and turned over, and after that, pressure may be applied with a breaking bar or the like to side A of the substrate, which is the rear side of side B of the substrate, so that side B of the substrate is broken.